STUDIES ON THE CONIDIAL COLOR CHANGE IN ASPERGILLUS FUNGI

PART II. THE ROLE OF COPPER AND HALOGEN IONS IN THE FORMATION OF GREEN CONIDIA

Abstract

By cultivating a green strain and a yellow mutant in media lacking copper and/or halogen ions, the responsibility of these ions upon the development of green color of conidia was studied.
1. The green strain took up a larger amount of copper into its mycelia when it was cultivated in a medium containing copper ion.
2. The yellow mutant could take up a sufficient amount of copper to produce green conidia only when halogen ion was supplemented together with copper ion.
3. By a comparison test with other color mutants, the yellow mutant was proved to be extremely poor in the ability of copper uptake.
On the ground of these bases, it was concluded that the development of green color of conidia in these strains is closely related with the ability of copper uptake and that halogen ion can restore the genetic defect in the copper uptake system.